(Portland, OR) -- A Portland woman is behind bars on child sex trafficking charges. A group of multiagency law enforcement officers arrested 21-year-old Shanell Rix Monday at an apartment complex in the 8200 block of Northeast Sandy Boulevard. Police say officers reported to the apartment after learning that a missing girl from out of state was there. Rix is facing charges of compelling prostitution, promoting prostitution and attempting to use a child in display of a sexually explicit act.